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BURIED OYSTER SHELL RESOURCE EVALUATION 

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EASTERN REGION OF THE ALBEMARLE SOUND 



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BURIED OYSTER SHELL RESOURCE 
EVALUATION OF THE EASTERN REGION 
OF THE ALBEMARLE SOUND 



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NORTH CAROLINA 

DEPARTMENT OF NATURAL AND ECONOMIC RESOURCES 

DIVISION OF EARTH RESOURCES 

GEOLOGY AND MINERAL RESOURCES SECTION 




RALEIGH 
1976 



BULLETIN 85 



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BURIED OYSTER SHELL RESOURCE EVALUATION 

OF THE 
EASTERN REGION OF THE ALBEMARLE SOUND 




NORTH CAROLINA 

DEPARTMENT OF NATURAL AND ECONOMIC RESOURCES 

DIVISION OF EARTH RESOURCES 

GEOLOGY AND MINERAL RESOURCES SECTION 




RALEIGH 
1976 



COVER PHOTOGRAPH SHOWS ALPINE "VIBRA CORE" BEING LOWERED 
INTO THE ALBEMARLE SOUND BY MEANS OF A BARGE-MOUNTED CRANE, 



Edited by: Edward R. Burt 

Layout by: Benjamin J. McKenzie 

Printed by: State Government Printing Office 

Additional copies of this publication are available from: 

Department of Natural and Economic Resources 

Earth Resources Division 

Geology and Mineral Resources Section 

P. 0. Box 27687 

Raleigh, North Carolina 27611 



BURIED OYSTER SHELL RESOURCE EVALUATION 
OF THE 
EASTERN REGION OF THE ALBEMARLE SOUND 



BY 






JAMES L. SAMPAIR 
IN COOPERATION WITH THE 
DIVISION OF MARINE FISHERIES 










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GEOLOGY AND MINERAL RESOURCES SECTION 

This section shall, by law ". . .make such examination, survey, and mapping of the geology, mineralogy, 
and topography of the state, including their industrial and economic utilization, as it may consider 
necessary. 

In carrying out its duties under this law, the section promotes the wise conservation and use of mineral 
resources by industry, commerce, agriculture, and other governmental agencies for the general welfare of 
the citizens of North Carolina. 

The Section conducts a number of basic and applied research projects in environmental resource plan- 
ning, mineral resource exploration, mineral statistics, and systematic geologic mapping. Services constitute 
a major portion of the Section's activities and include identifying rock and mineral samples submitted by 
the citizens of the state and providing consulting services and specially prepared reports to other agencies 
that require geological information. 

The Geology and Mineral Resources Section publishes results of its research in its own series of Bulletins, 
Economic Papers, Information Circulars, Educational Series, Geologic Maps, and Special Publications. For 
a complete list of publications or more information about the Section please write: Geology and Mineral 
Resources Section, P. O. Box 27687, Raleigh, North Carolina 2761 1. 



CONTENTS 

Page 

Abstract 1 

Purpose and scope 1 

Organization and acknowledgements 2 

Fieldwork 3 

Subbottom profiling 3 

Core sampling 5 

Office and laboratory work , 6 

Interpretation and results 7 

Area A 8 

Prospect 1 - Haul over Point 8 

Prospect 2 - Peter Mashoes Creek 8 

Prospect 3 - Collington Shoals 8 

Prospect 4 - Mashoes Light 8 

Prospect 5 9 

Area B 9 

Prospect 6 - Croatan Channel 9 

Area C 9 

Prospect 7 - Croatan Sound marker "21" 9 

Prospect 8 - position mark 23 10 

Prospect 9 - Cedar Bush Bay 10 

Dredging and the environment 10 

Physical effects 12 

Biological effects 12 

Recommendations 13 

Appendices 14 

1. Budget summary 15 

2. Equipment and personnel 16 

3. Selected seismic profiles 17 

4. Core logs 24 

5. Core hole locations range-range data . . . 46 

6. Future core points 47 



1 1 



ILLUSTRATIONS 
(Plates are in pocket) 



Plate 1. Bathymetry map 

Plate 2. Overburden thickness map 

Plate 3. Shell unit thickness map 



BURIED OYSTER SHELL RESOURCE EVALUATION OF THE 
EASTERN REGION OF THE ALBEMARLE SOUND 

by 
James L. Sampair 



ABSTRACT 



Two hundred and sixty three miles of subbottom profiling were done in the lower Albemarle Sound, 
Roanoke Sound, and Croatan Sound using a Raytheon RTT 1000, 3.5 Khz "pinger". This was followed by a 
core program using an Alpine Geophysical 20 foot "Vibra Core". Sixty cores were taken at tie points 
and on sedimentary structures indicated by the geophysical profiles. 

Three broad areas of interest were defined for the presence of buried shell deposits, and nine 
prospects are indicated on maps attached to this report. The bathymetry, the overburden thickness, 
and the shell unit thickness are also indicated on the maps. Five permanent files were set up in the 
Geology and Mineral Resources Section: one containing color slides of the cores taken, one containing 
strip logs of the cores (consisting of color photographs with written lithologic descriptions), one 
consisting of a sample file containing five cuts each of all of the cores, one containing the geo- 
physical profiles, and one containing a computerized file of navigation data. There is also a 10 
minute, 16mm film of the various elements of the field operation on file with the Division of Marine 
Fisheries. 

As a result of this study, we estimate a potential for 30.6 million cubic yards of oyster shell 
in the study area, with a current raw material market value in excess of $90,000,000.00. A one-dredge 
operation would take a little over 20 years to extract these shells and would employ 90 people year 
around at an average annual payroll of $900,000.00. 

PURPOSE AND SCOPE 

This study is the first step in a program of the Department of Natural and Economic Resources to 
locate and map the calcium carbonate shell deposits in the bays, estuaries, and sounds of eastern North 
Carolina. It is a principle objective of this program that both the environmental and the economic 
impacts of utilizing the shell resources be understood. The area covered by this study includes lower 
Albemarle, Croatan, and parts of Roanoke Sounds (see Plate 1). 



The study developed suitable techniques for accurately locating shell reefs and associated sediments 
by rapid reconnaissance of large marine areas at reasonable costs. A subsurface coring method was 
developed for sampling and measurement of the shell deposits located during reconnaissance. 

Data on thickness and type of overburden, thickness and type of shell and matrix material, and 

i 
lithology and sequence of the associated sedimentary sections were derived from the field techniques 

utilized in this study. Data on sedimentary mineralogy, stratigraphy, sedimentary structure, and 

paleontology are available from photo strip logs of the cores, color slides of the cores, cuts of the 

actual core material, and seismic profiles. These materials are on file with the Geology and Mineral 

Resources Section and can be used to support future geologic studies and mineral resource evaluations 

as well as water-use planning studies. All data collection points are precisely located by range-range 

data and by Carter Coordinate data which have been computerized. 

In addition to indicating the location of the shell deposits encountered in coring, this report 
provides thickness maps of both the oyster shell and overburden and a discussion of the materials, 
geology, and possible environmental impacts. 

ORGANIZATION AND ACKNOWLEDGEMENTS 

The contractor for this project was the Department of Natural and Economic Resources. The Division 
of Earth Resources and the Division of Marine Fisheries of this Department were assigned the task of 
executing the contract. Mr. Stephen G. Conrad, Director of the Division of Earth Resources, had primary 
responsibility for organization and administration of the project. 

The author, Geologist-in-Charge of the Coastal Plains area for the Geology and Mineral Resources 
Section of the Division of Earth Resources, and Mr. James Brown, Assistant Director for Marine Fisheries, 
were given responsibility for the execution of the necessary studies and for reporting the results. 

There are many people whose efforts resulted in the timely completion of this project. The author 
would like especially to thank Loi Priddy with Marine Fisheries who was a "jack of all trades" in the 
project, in particular for his work in surveying, navigation, and computer technology; Orvill Til let of 
the Enforcement Division of Marine Fisheries was our very able boat captain during the geophysical 
survey and also helped us whenever he could during the coring operation; Jim Tew and Fentress Mundane 
of Marine Fisheries found it necessary at times to revise their plans and schedules in enforcement and 
oyster rehabilitation in order to make people and equipment available to this project; and Jim Coffey, 



staff geologist in the Coastal Plains area, did the photography on the cores and prepared many of the 
illustrations and maps for this report. There are others in Marine Fisheries and in Earth Resources 
who made substantial contributions to the drafting, manuscript, and budget management whom we would 
also like to thank for their time and effort. 

FIELD WORK 

The field work was accomplished in two steps. A reconnaissance reflection seismic survey of the 
study area and shallow coring aided in correlation of the seismic data and in testing specific 
anomalies noted on the seismic profiles which were thought to be prospective shell deposits. The 
volume of coring was limited by budget constraints but was sufficient to prove the method. 

Subbottom Profiling 

The principle constraints in deriving specifications for this part of the project were cost per 
unit coverage, speed, and depth of investigation. A shallow-survey reflection seismic system seemed 
to be suited for the purpose and the following systems were investigated: the E.E.G. Uniboom, the Edo 
Western 7 and 3.5 Khz Transducers, and the Raytheon 3.5 Khz Transducer. 

Due to the 10-foot average depth of the water, the cost of equipment, and the non-critical penetra- 
tion requirement, the Uniboom was not considered in detail. Because of the water depth and the uncon- 
solidated nature of the sediments to be investigated, the low frequency 3.5 Khz transducer unit was 
selected as the optimum tool. Raytheon was low bidder on this equipment. Special mounting equipment 
was designed by the author and Loi Priddy of Marine Fisheries so that the equipment could be installed 
on an eighteen-foot boat furnished by James Tew, Chief of Enforcement of Marine Fisheries. 

Navigation was the next concern. It is essential that sites from which data is acquired be located 
sufficiently well so that they can be easily relocated for future work. Degree of accuracy, cost, 
power requirements, ease of installation, and effective operational range were all considerations. Costs 
and timely availability varied widely for this equipment. The Motorola Mini-Ranger system with an 
Anadex paper tape recorder was selected on the basis of cost and service. This system served very 
faithfully with an accuracy of ±10 feet out to distances of twelve miles from shore stations. Had we 
also included a punch tape recorder, a savings in time and money could have been effected in the sub- 
sequent computerization of the navigation data. The author was not aware early in the planning of this 
project that a "Cal Comp" plotter would be part of the computer hardware available to the program from 



North Carolina State University. Because of budget limitations, we had only considered hand plotting 

the data. In order to make use of the "Cal Comp" plotter, the data from the Anadex recorder had to 

be key punched. Loi Priddy and Dr. David Link of the Computer Science Department at NCSU developed 

the program to convert the range-range data from the Anadex recorder to the Carter x-y coordinate 

* 
system and plot the boat tracks using the "Cal Comp" plotter. 

The activities and location data printed on the maps (in pocket) included in this report display 
the seismic survey network as plotted by "Cal Comp" plotter. One can see in reviewing the network 
that an automatic pilot on the boat would have also been of considerable assistance. 

The seismic equipment emits a signal at a frequency of 3.5 Khz. On the Raytheon equipment, the 
impulse rate, strength, and phase are adjustable in the hope that the operator may find the combination 
that best defines the sedimentary section and achieves the most satisfactory penetration. The impulses 
are reflected from velocity interfaces starting with the water-bottom contact and are received by the 
transducer in a recording mode. These signals are transmitted to a Raytheon recorder which is typical 
of their research fathometer unit. 

In very shallow water, a multiple reflection of the water-bottom contact appears on the record at 
a depth below the contact equal to the water depth. Unfortunately, in this situation, the multiple 
appears in the portion of the record that is of greatest interest to this study. Adjusting the 
instruments for signal strength and timing minimizes this problem but does not eliminate it. 

The results achieved from the reconnaissance survey vary from poor to very good. In part, the 
variation was due to the operator's improving technique as he gained experience with the equipment and 
in part to water depth and sediment type. A total of 263 profile miles of seismic lines, represented 
by the boat tracks printed on the maps (in pocket), were achieved at an approximate cost of $40.00 
per profile mile. 

A preliminary review of the data was carried out to determine the best possible location for our 
core sampling program. We determined that in addition to coring some sedimentary structures that 
appeared to be shell deposits, we would need coring to tie the intersections of our seismic profiles 
to determine reasonable sedimentary correlations. The lateral sedimentary facies relationships are 
extremely complex. 



Core Sampling 

Two important constraints entered into consideration of a coring technique for this study. First, 
the budget was extremely limited for this sort of work which is quite expensive to do even on land. 
Second, we presumed that dredging, because of the environmental hazards, would be limited to depths of 
thirty feet or less. The author realizes there may be considerable controversy on this point; however, 
such a limitation would have been necessary in any event in order to get any appreciable tie data for 
the seismic data, given the budget constraints. 

There are basically only two ways this coring could be done. The first method would be to employ 
a drilling machine equipped with core barrels mounted on a barge that could be anchored in a very 
stable manner both horizontally and vertically. Because of the mobility of the water and the penchant 
for the winds and weather to change drastically over very short periods of time (15 to 20 minutes on 
occasion), this method is very costly in relation to the amount of coring that can be accomplished. A 
second method of coring is to drive coring tubes with a hammer using a barge as a platform. Among the 
specific methods for doing this is a device developed by Alpine Geophysical Company called the "Vibra 
Core". In this method a steel tube containing a plastic liner is mounted in an aluminum frame. An air 
hammer device is mounted on the steel tube in such a way as to allow the tube to be driven into the 
bottom. The tremendous advantage of this device is that the unit can be operated over the side of a 
barge without anchoring the barge. The unit is picked up by a crane and set over the side on the 
bottom. Air lines connected between the barge and the air hammer and a cable attached between the 
barge and the coring device are the only connectors between the two. This allows as much as 100 feet 
of lateral movement by the barge, and common vertical movement of the barge is not disruptive. The 
principal limitation of the device is the length of core that can be taken. Alpine builds this unit 
with 20 ft., 30 ft., and 40 ft. core barrels. A second limitation is the fact that during the coring 
operation, the sediments can sometimes pack in such a way as to lock in the barrel. The operation will 
not secure a full core in this situation. Also, when a lithology is encountered that is too indurated 
to be penetrated, such as a limestone or a well-cemented sandstone, incomplete coring of the section 
results. In unconsolidated sediments of the type normally found in shallow marine environments and 
where the requirements are for data in the top 40 feet, this device is clearly the best answer. 

During our operation, a converted ferry boat, which is used regularly by Marine Fisheries in their 
oyster rehabilitation program, was provided by Mr. Fentress Mundane, the Director of that program, as our 
working barge. A 30 B crane was loaded on the barge together with a 900 CFM compressor and 5 KW generator. 
A 20-foot "Vibra Core" was leased from Alpine Geophysical Company and two of their operators were pro- 
vided as a part of the lease package. For navigation the Motorola Mini-Ranger was used. 



As can be seen on the maps (in pocket), we attempted to locate the core sites at the tie points 
and on the ends of seismic lines as well as at points where shell was suspected. The mini-ranger 

makes precise relocation possible; however, because of high priority of time, we settled for 

i 

approximate relocation in most cases rather than spend time maneuvering the barge for an exact 

relocation. A total of sixty cores were taken totaling approximately 1000 feet of core at a cost of 
approximately $20.00 per foot. 

OFFICE AND LABORATORY WORK 

The data acquired from the seismic survey are presented in the form of a continuous record section. 
The vertical scale of the section is in feet and the horizontal scale is related to feet indirectly by 
means of position marks which were recorded on the record sections and the navigation data. These 
position marks were plotted on the record sections so that all of the seismic data can be located on 
the ground with considerable precision (±3 feet). The appendices contain some examples of the seismic 
data in the vicinity of located shell deposits. All the seismic data are on permanent file in the 
Geology and Mineral Resources Section of the Division of Earth Resources and may be reviewed by con- 
tacting the Section. 

The cores were retrieved in plastic barrels that are 20 feet long and 3.5 inches in diameter. For 
ease in handling, the cores were cut into 3 foot lengths. In the laboratory these 3 foot sections were 
split lengthwise with a diamond saw and were then photographed and described as to lithologies and 
shell content. Two types of photographs were taken: 4X5 inch color prints and 35 mm color slides. 
Five cuts of each core were then preserved in plastic bags for future studies of paleontology, sedi- 
mentary petrology, and whatever other geologic studies may arise for which the data would be useful. 
From those cores, in which oyster or clam shells were encountered, a large sample was taken for volume 
analysis of the components in the shell section plus chemical analysis of the shell to determine the 
percentage of calcium carbonate. Sample logs were hand plotted for the ten holes which indicated 
possible commercial shell deposits. These logs are included with this report. 

Although the color prints were not reproduced for the published report, they, along with 340 
color slides, are a part of the permanent file. Both the prints and the slides are available to any 
interested person for viewing at the laboratory of the Geology and Mineral Resources Section in 
Raleigh. Copies can be made of all or any part of the set of color slides at additional cost. 



INTERPRETATION AND RESULTS 

Two steps were necessary 1n the interpretation of the subbottom profiling data. Prior to the 
coring operation, the profiles were reviewed in some detail to determine if sedimentary structures seen 
on the profiles could be interpreted as shell beds. We assumed that the shell would present a very 
hard, seismically fast layer which would generate a reflection on the profiles. To aid this determina- 
tion, we had some core data which had previously encountered shell. We picked 94 sedimentary structures 
in this manner and located 200 coring sites. The maps included with this report indicate the location 
of interesting sedimentary structures noted during this analysis which we did not core, as well as the 
location of 60 core holes. 

Upon completion of the coring and analysis of the lithology, the core data was plotted on the 
seismic profiles. The intervals in which shell material was encountered were then correlated on the 
seismic profiles in an attempt to establish the lateral extent and thickness of the deposit. We were 
somewhat frustrated in this attempt by the fact that bedding of any sort has a very erratic lateral 
extent in the upper twenty feet of sediment in this area. We were unable to correlate any unit further 
than a mile without substantial changes in lithology. This suggests very rapidly shifting sedimentary 
environments with changing rates of depositional energy. The range of clastic sediment sizes and types 
testify to open bay, stream channel, back bay, beach, and deltaic regimens in areas that are now all 
open bay. These paleoenvironments are all represented in the top 15 feet of sediment. 

Because it is impossible to contract for this type of coring on other than some sort of cost plus 
basis and because the budget was very limited, we designed the coring program so that we could suspend 
operations when the money ran out. That situation occurred after ten days of operation, during which 
we secured 60 cores. 

Ten of the cores that were taken encountered 1 foot or more of shell material. Each of these 
sites, after review of the seismic data, were mapped for bathymetry, overburden thickness, and shell 
thickness. Since the oyster shell unit exhibited more continuity across the study area, it was the 
unit which was mapped and from which reserves were calculated. The scattered clam shells and shell 
hash were not mapped. The shell isopach maps included with this report show the oyster shell thickness 
at each of these core sites. As the maps indicate, there are three broad areas of interest designated 
A, B, and C. Within these areas there are nine shell prospects. One through five are in Area A, six 
is in Area B and seven, eight and nine are in Area C. Core logs included with this report as Appendix I 
contain a description of the lithology, a sieve analysis of the shell sections, and an acid test of the 
shell to give an approximation of the CaC0 3 content where the shell was thick enough to be commercial. 



Area A 



Prospect 1 - Haulover Point 

In this area 3 cores were taken that encountered 1 foot or less of clay with scattered oyster 

I 
shells. The volume encountered was not commercial; however, the area warrants more coring. Three 

core logs, numbers 42, 43, and 44, in Appendix 4 describe the sedimentary section. No screening 

or other laboratory tests were carried out on samples from this site. 

Prospect 2 - Peter Mashoes Creek 

Substantial shell was encountered in this area in five cores, numbers 38, 39, 40, 55, and 57. 
There are actually two shell banks in this area; one consists of oyster shells in a clay matrix, and 
the other contains clam shells in a sand matrix. As stated previously, the oyster shell unit was 
more contiguous and was the unit mapped. In a 2 mile long by 3000 foot wide area, there is a 
potential for 8,960,000 cubic yards of oyster shells which averages 99.5% Ca^. The site needs addi- 
tional coring to determine the precise shell reserves. The shell occurs in the top 10 feet of sedi- 
ment and dredging would require some sediment control since the shell occurs in a plastic clay matrix 
which would present some settling problems. Using a fairly coarse screen, perhaps 1/4" mesh, would 
minimize the problem since the clay would not be completely disintegrated in this process (see dis- 
cussion on dredging and the environment). 

Prospect 3 - Collington Shoals 

Shell was encountered in three cores, numbers 58, 59, and 60, which indicate an area of about 3 
square miles containing an average of one foot or less of shell in a clay section 4.5 feet thick. The 
section is in the top 6 feet of sediment. The matrix is the same as in prospect 2, and the comments 
regarding dredging also apply here. The reader should also understand that since everything but the 
shell is returned to the sound bottom, no substantial change in water depth is likely to result from 
dredging this shell body. We can estimate a potential of 15,000,000 cubic yards of shell in this area. 

Prospect 4 - Mashoes Light 

Core number 35 had about 1.1 feet of oyster shell, all within the clay section. This by itself is 
not commercial. However, shell occurs in a plastic clay unit throughout this area, and the clay unit is 
5.4 feet thick in this core. Additional coring in the vicinity of this core should reveal a thicker shell 



section. The seismic profile, line 4W, indicates that there is clay with possible shell 1,430 feet 
along the profile. No laboratory testing was done on this core. 

Prospect 5 

Three cores encountered oyster shell in this area, 28, 30, and 52. Seismic profile 2W indicates the 
possibility that the oyster shell unit may be continuous from core hole 58 in prospect 3 to core hole 
28 in this prospect. That is, the clay bed that the shell occurs in could be continuous. The amount 
of shell present must be determined by additional coring. We can say that everywhere along the line 
that a core was taken at least 1 foot of oyster shell was encountered, and those shells overlay a 
coarse sand unit that contains shell hash and clam shells. The southern portion of the area covered 
by this prospect has an oyster shell potential of 3,000,000 cubic yards, not counting the clam shells. 
There is also sand and gravel in this prospect which was not evaluated. 

As elsewhere, the oyster shells occur in a clay matrix which in this case is 4 to 9 feet thick. 
Shells are generally scattered throughout this unit but may be locally concentrated. It should be noted 
that while shell nearly always occurs in relationship with the shoal areas in the sound, the deposits are 
by no means restricted to these areas. The CaC0 3 solubility test reveals the oyster shells to be 94% 
to 96% CaC0 3 , and the clam shell material to be about 80% CaC0 3 - 

Area B 

Prospect 6 - Croatan Channel 

This prospect lies between channel marker "13" and "11" about 70 yards west of the channel marked 
on USC and GS chart 1229. One core, number 14, located at the intersection of seismic profiles S and V 
encountered the clay unit at 1.7 feet and cut 7.3 feet of clay with 3.0 feet of oyster shells. Approxi- 
mately 19.6% (or 0.6 feet) of the interval is shell. The CaCO solubility test indicates the shell to 
be 98.6% CaC0 3 . Review of lines S and V indicates the deposit is approximately 500 feet wide in the 
east-west direction and 2000 feet long along line V. The potential is about 160,000 cubic yards. The 
seismic profiles show indications east and west of profile V where additional coring could prove productive. 



Area C 



Prospect 7 - Croatan Sound Marker "21 



This prospect lies on the east side on the Croatan Channel between marker "19" and "21" on the USC 

and GS chart 1229. The shell unit is encountered in core hole number 12 at 1.7 feet and extends to 2.2 

feet. Seismic profile V indicates the unit may extend approximately 2000 feet north-south. Previous 

coring done in the vicinity by Langenfelder Associates indicates the unit is widely present in the area, 

I 
particularly south to prospect 9. Additional coring will be necessary in order to estimate the full 

shell potential (see discussion on prospect 9). 

Prospect 8 - Position Mark "23" 

This site must be located with the navigation data. Position mark "23" can be found on seismic 
profile U and core hole number 8 is just south of the position mark on line U. This core hole penetrated 
20 feet of clay and very fine sand typical of the oyster shell unit. Oyster shells were encountered in 
the core from 17.2 feet to the bottom of the hole, and we had not penetrated below the oyster shell bear- 
ing unit at that point. About 13% of the section is oyster shell containing 94.9% CaCO^. The seismic 
profile indicates that the unit is continuous southward for another 2000 feet. There are also indications 
of areas worthy of additional coring northward along line V. We can estimate a minimum potential in the 
vicinity of core hole number 8 of 230,000 cubic yards of oyster shells. 

Prospect 9 - Cedar Bush Bay 

Core hole number 11 in this study and five core holes drilled by Langenfelder Associates encountered 
an average of 2 feet of shell in a clay section approximately 6 feet thick. In core hole number 11 the 
shell unit starts at 0.9 feet and extends to 3.3 feet. The section is approximately 23.6% shell which 
contains 97.5% CaC0_. Additional coring needs to be done to outline all of the reserves in this area. 
We estimate the shell potential at 1,200,000 cubic yards. 

DREDGING AND THE ENVIRONMENT 

There is a fundamental law in geology called the doctrine of uniformitarianism. This doctrine says 
that the key to the study of past physical processes is the observation of present physical processes. 
If this dictum is reversed in the present study, a very important conclusion can be reached. That is, 
any attempt at preservation in the marine areas under study is doomed to certain failure with time. This 
statement applies to attempts to preserve one area as fresh water or another as saltwater. It applies to 
attempts to preserve bathymetry. It applies to attempts to preserve marsh in one area and open water in 
another. The certain lesson to be learned from a review of the top 20 feet of sediments in the bottom of 



10 



the sound is that rapid change is the rule here, most certainly not the exception. What we may consider 
of economic or aesthetic importance today is not to be handed down to future generations in the present 
form. The natural processes that rule this area are marshalled in opposition to the status quo. A mere 
6 foot rise in sea level would virtually rewrite the face of the entire area. Such movements have 
occurred continuously over the past few thousand years as is indicated by the sediments recovered in this 
study. Much more recently, Currituck and Albemarle Sounds were saltwater bodies year around fed not only 
by Oregon Inlet but also by an inlet in the vicinity of Corolla. It was during this period that the shell 
deposits currently under investigation were formed. 

The present water depth throughout the area averages less than 10 feet. With the very large open 
expanses available to the wind, such a shallow water environment will stir and constantly move bottom 
sediments. The water will be very turbid during bad weather. Salinities will and do vary widely with 
wind and with seasonal runoff brought into the sounds by the rivers. Seasonal water temperature changes 
are also the norm. All of these factors suggest that the marine biota that subsist here are very flexible 
and that man's activities can, at most, temporarily influence only a minor portion of the system 
detrimentally. 

Generally speaking, the following catagories of subjects bear on a marine ecosystem: physical 
aspects - salinity, bathymetry, currents, turbidity, and temperature; biology - varieties of fish, benthic 
and foraminiferal invertebrate biota, water fowl, and the food chain (plant and animal); chemistry - 
chlorinated hydrocarbons in organisms and sediment column, pesticides, PCB and trace metals in sediment 
column, and contained water; geology - type and distribution of sediments and sedimentary structures; and 
economics - the economics of shell dredging versus the economic hazards to fish and marine biota nurseries, 
to sports and commercial fishing, to water recreation, or other economic or aesthetic use of the water 
environment. 

To keep the discussion from evolving into a discourse on marine biology and physical oceanography, 
the subjects will be dealt with in terms of dredging. This is an alternative to the baseline approach 
which is recommended when an entire area is subject to environmental change and there is to be an attempt 
to monitor the direction and rates at which change is occurring. 

The process of dredging for shell involves cutting into the bottom of the sound to some predetermined 
depth, sucking the sediments up by use of large pumps, discharging the gross pumpage across screens, and 
returning to the sound bottom all but the shell of predetermined size. The discharge back to the sound 
is by gravity settling. 



11 



Physical Effects 

Dredging could affect salinity in three ways. The material being cut into could contain large per- 
centages of NaCl . If the bathymetry is substantially changed, currents of saline water could encroach 

I 
into areas where they would not normally go. Finally, the dredge could encounter a fresh or salt water 

acquifer under a clay seal with positive pressure. We can say with certainty that none of these con- 
ditions will be met in the areas so far studied. 

Water depth can be substantially changed as a result of dredging. However, in the area under study 
the concentration of shells suggests that the normal total change will be no more than 2 feet. 

Dredging has only a nominal effect on current as in the case of transgressing salt water. However, 
it is important to know the current patterns in an area for different cases of wind, tide, and river 
discharge in order to predict any adverse siltation effects brought about by dredge discharge. 

Turbidity looms as a problem in the study area primarily because the oyster shell deposits were 
all associated with a matrix of plastic clay and very fine-grained quartz sand. Considering the 
relatively small area a dredge can cover as opposed to the turbidity caused in this area by a high wind 
and the obvious additional fact that the biologic environment has adapted to considerable turbidity 
because of the natural processes at work in the area, the logical conclusion is that any damage done by 
dredging will be local and temporary for most of the study area. Marsh area would have to be given very 
special attention, however, since both marine biota and water fowl depend on the marsh environment, and 
even temporary destruction would have some disastrous short term economic impacts. 

Biological Effects 

Fin fish can be affected in two ways by dredging: first by an increase in turbidity and second by 
a possible disruption of their normal food supply. The local nature of dredging normally causes only a 
change in fish habitat during the dredging operation. These statements are also true for benthic biota 
which can move to avoid the dredge and return when favorable conditions are re-established. Bottom 
dwelling organisms which are an important element in the food chain are destroyed by dredging and 
normally require two or three years to re-establish themselves provided bottom conditions have not been 
so altered as to make that impossible. Great care needs to be exercised in determining areas to be 
dredged so as to minimize this hazard. Areas with substantial plant food for water fowl also need to be 
avoided or the plant regimen needs to be re-established after dredging. 



12 



A lot of rhetoric has been offered regarding the potential danger of resuspending sediments that 
may contain chemicals adverse to the biota. A number of cores, particularly clays, contained connate 
water with hydrogen sulfide gas. If released in sufficient amounts, this gas could be chemically 
adverse to the biota, but this would require a rather massive resuspension not contemplated by shell 
dredging. 

As was mentioned in the section dealing with interpretation of data, the oyster shell material is 
contained in a matrix of plastic clay and very fine-grained quartz sand. This is typical of a deposi- 
tional environment with a very low energy level. The shell units frequently overlay a coarse sand and 
shell hash unit which is typical of a forebeach environment. The overburden, if any occurs, is usually 
clay or fine sand. Typically, the clay material is a stiff to very plastic material which does not 
easily disintegrate in water. It is our opinion that screen sizes will be important in reducing 
turbidity with this clay in any dredging operation. 

Based on data obtained by the Army Corps of Engineers in environmental impact statements on San 
Antonio Bay in 1971, one dredge can produce approximately 1,500,000 cubic yards of shell per year with 
a value of approximately $3,000,000.00. The operation would employ the services of about 90 people, 32 
barges, and 8 tug boats. The average annual payroll would amount to $710,000.00. The material is valued 
as a source of chemical grade lime, as poultry grits, and as oyster clutch material. It also can be used 
to manufacture portland cement. The foregoing is offered in the environmental section of this report 
because it is needed to compare the value of alternative resources. 

RECOMMENDATIONS 

The next logical step would be a closely supervised test dredging project. We recommend the Cedar 
Bush Bay Area as a good place to conduct such a test. Prior to testing, base line data should be 
gathered at the site so that the area can then be monitored for any adverse environmental impacts. 
Particular attention should be given to the possible adverse effects of siltation and turbidity. 

We further recommend that additional funds be sought to complete the coring program in this area. 
The data should be reviewed not only for shell but for a sand and gravel inventory. Substantial gravel 
deposits were noted during this study. Since the northeastern section of North Carolina is in very 
short supply of these commodities, the feasibility of extracting these materials at the same time as the 
shell needs to be evaluated. 



13 



APPENDICES 



14 



APPENDIX 1: BUDGET SUMMARY 

CPRC Funds 

Lease and rental of equipment, travel expenses, and purchase of expendable supplies 

through June 30, 1975 $ 8,498.00 

Lease and rental of equipment, travel expenses, and purchase of expendable supplies 

and equipment through June 30, 1976 26,502.00 

TOTAL $35,000.00 

North Carolina Department of Natural and Economic Resources Funds 

1. Through June 30, 1975 

Division of Earth Resources $ 4,679.44 

Division of Marine Fisheries 3,444.60 

TOTAL $ 8,124.04 

2. Through June 30, 1976 

Division of Earth Resources $12,886.21 

Division of Marine Fisheries 9,359.15 

$30,369.40 



15 



APPENDIX 2: EQUIPMENT AND PERSONNEL 

1. Geological and geophysical field and interpretive personnel and equipment. 

a) Two geologists and one geologic technician as needed. Two technicians, part time, as needed. 
(Division of Earth Resources) 

b) RTT-1000 Raytheon 3.5 Khz subbottom profiler on lease from Raytheon Corporation. 

c) Alpine Geophysical Company 20 foot "Vibra Core" and two technicians on lease from Alpine 
Geophysical Company. 

d) Crane, 900 cfm air compressor and miscellaneous equipment on lease from Waff Brothers Heavy 
Equipment Company. 

2. Navigation, boat location, survey personnel and equipment. 

a) A registered surveyor and one technician. (Division of Marine Fisheries) 

b) Range-range boat positioning equipment, the Motorola Mini-Ranger, on lease from Motorola 
Corporation. 

3. Boat operators, boats and barges, as needed. 

a) One seventeen foot and one fifteen foot boat as needed with operator. (Enforcement Division 
of Marine Fisheries) 

b) One self-propelled barge with a 3 man crew as needed in the coring operation, (oyster 
rehabilitation program of Marine Fisheries) 

4. Computer technology and hardware to handle the navigation data. 

a) One computer specialist from Marine Fisheries and two program analysts on contract from the 
Computer Science Department of North Carolina State University as needed to convert range-range 
data to x-y coordinate data and plot the boat tracks using the "Cal Comp" plotter. 

5. Marine biology and physical oceanography, as needed. (Division of Marine Fisheries) 

6. Administrative support was provided by each Division handling records and invoices for personnel 
and equipment furnished for the project. Mrs. Myrtle Tyson handled budget management on behalf of 
Mr. Stephen Conrad. 



16 



APPENDIX 3: SELECTED SEISMIC PROFILES 



17 




6 



to 



APPENDIX 4: CORE LOGS 



24 



SEA LE V EL 



AREA C PROSPECT 8 



-10 -Wo 



dark- to light-gray, plastic clay 



-20 -E= 



11.0' 
12.0' 



very fine-grained sand with some clay 



plastic clay with fine-grained sand 



■30 



17.2' . 
18.0' 1| 

20.0* JS 



clay with sand and oyster shell 
as above 



-40 ■ 



Note: The core was not deep enough to evaluate total shell 
thickness, so the seismic interpretation of a total 
of 7 feet was used. 



Shell Unit Screen Analysis 
Screen Size Sample WT . Percent 



.1574" 


71.2 gms 


13.1% 


.0787 


8.7 


1.6 


.0394 


19.9 


3.7 


.0197 


60.3 


11.1 


.0098 


141.8 


26.0 


.0098> 


243.1 


44.5 



The commercial shell was retained on the 
0.1574" screen. These were oyster shells, 
A 20% HC1 solution digested 67.6 gms or 
94.9% and left a residue of 3.6 gms or 

5.1%. 

The estimated 7 foot segment analyzed 
contained .92 foot of shell. 



SEA LEVE L 



BOTTOM 



f o 

0.9' 



■10 



-20-; 



■30- 



-40 



5.7' 
9.4' 



15.0' 



CORE NUMBER 11 
AREA C PROSPECT 9 



♦ 

dark plastic clay 

very fine-grained sand with clay and oyster shells 

as above 

as above with clay increasing 



very fine- to fine- to medium-grained sand; grading downward 



coarse-grained sand-gravel 



Shell Unit Screen Analysis 
Screen Size Sample MT. Percent 



.1574" 


127.0 gms 


23.6% 


.0787 


15.4 


2.9 


.0394 


17.5 


3.3 


.0197 


46.0 


8.6 


.0098 


149.4 


27.8 


.0098> 


182.9 


33.8 



The commercial shell was retained on the 
0.1574" screen. These were oyster shells. 
A 20% HC1 solution digested 123.8 gms or 
97.5% and left a residue of 3.2 gms or 

2.5%. 

The 2.4 foot segment analyzed contained 
0.57 foot of shell. 



26 



SEA LEVEL 



CORE NUMBER 12 
AREA C PROSPECT 7 



llOTTOM 



-10 - 



o 

1.7 
2.2 



]. 



very fine- to fine-grained sand with some clay 
shell unit as above with oyster shell 



-20 - 



-30 - 



-40 



13.0 



very fine- to fine-grained sand with some clay 



27 



SFA LEV 



1 



LUKL IWIBLK 14 

AREA B PROSPECT 6 



-10 - 



IDHQII 



o 

1.7' 
3.0' 



z20 




-30 - 



15.0' 
17.6' 



fine- to medium-grained sand with some clay 
very fine-grained sand with clay; minor shell 

dark plastic clay; scattered shells 

as above with oyster shells 

as above 

dark plastic clay 

very fine- to fine-grained sand with clay 
fine- to medium- to coarse-grained sand 
as above 



-40 



Shell Unit Screen Analysis 



Screen Size 


Sample 


WT. 


Percent 


.0787" 


105.7 


qms 


19.6% 


.0394 


9.1 




1.7 


.0197 


4.5 




0.8 


.0098 


22.3 




4.1 


.0049 


187.8 




34.8 


.0049> 


211.0 




39.0 



The commercial shell was retained on the 
0.0787" screen. These were oyster shells. 
A 20% HC1 solution digested 104.2 gms or 
98.6% and left a residue of 1.5 gms or 1.4%. 

The 3.0 foot segment analyzed contained 
0.59 foot of shell. 



28 



n SEA LEVEL 



CORE NUMBER 23 
AREA A PROSPECT 5 



-10- 



liOTTOI 



3.8' 



very fine-grained sand with clay and few shells 



as above with scattered oyster shells 



■20 -r 



9.4' J £ 



as above with oyster shells 



15.2' 



■30 



-40 



very fine-grained sand with clay 



29 



SEA LEV EL 



AREA A PROSPECT 5 



imw<\ 



-10 



plastic clay 



6.7' 
7.7' 



plastic clay with oyster shell 



-20-1 



fine- to medium-grained, gray to yellow, quartz sand 



15.2' 



-30 



-40 



30 



SEA LEVEL 



-10 



ijfiTTOn 



-20- 



■30- 



-40 



3.0' 

4.3 

5.4 



■ 3s 



12.0' 



CORE NUMBER 35 
AREA A PROSPECT 4 



very fine-grained sand with some clay 

dark plastic clay 

dark plastic clay with some oyster shell 



very fine- to medium-grained, light-gray sand; some coarse- 
grained layers 



31 



SEA LEVEL 



CORE NUMBER 38 
AREA A PROSPECT 2 



-10 



-20 



-40 



\0TT0 



2.2' 
3.0' 
3.5' 

4.6' 

6.0' 
6.8' 



9.0' 
9.9' 



dark plastic clay 

| fine- to medium-grained sand; minor shell 

? n clay with fine-grained sand; some oyster shells 

% very fine- to medium-grained sand with clam shells 

fine- to medium-grained sand with abundant clam shells 

as above 

medium- to coarse-grained, gray sand 
medium- to coarse-grained, yellow-tan sand 



Shell Unit Screen Analysis 
Screen Size Sample WT . Percent 



.1574" 


263.6 gms 


48.6% 


.0787 


27.7 


5.1 


.0394 


26.4 


4.9 


.0197 


65.1 


12.0 


.0098 


119.7 


22.1 


.0098> 


39.9 


7.3 



The commercial shell was retained on the 
0.1574" screen. These were clam shells. 
A 20% HC1 solution digested 255.8 gms or 
97.1% and left a residue of 7.8 gms or 2.9%. 

The 0.5 foot segment analyzed contained 
.24 foot of clam shells. The analyzed 
section was not the oyster shell unit and 
therefore was not mapped as reserves. 



32 



SEA LEV EL 



CORE NUMBER 39 
AREA A PROSPECT 2 



-10-™ 



TTOM 



very fine- to fine-grained sand with clay 



4.6' 

6' 

6.6' 

8.3 1 



very fine- to fine-grained sand 

dark plastic clay with some sand and oyster shells 
as above 

very fine-grained sand with some clay 



-20- 



medium- to coarse-grained sand with shell hash 



13.6' 



■30 - 



-40 



Shell Unit Screen Analysis 
Screen Size Sample WT . Percent 



.1574" 


98.8 


gms 


18.3% 


.0787 


15.8 




2.9 


.0394 


13.7 




2.5 


.0197 


8.2 




1.5 


.0098 


112.2 




28.8 


.0098> 


290.0 




46.0 



The commercial shell was retained on the 
0.1574" screen. These were oyster shells. 
A 20% HC1 solution digested 96.6 gms or 
97.8% and left a residue of 2.2 gms or 2.2%. 

The 2.0 foot segment analyzed contained 
0.37 foot of shell. 



33 



SEA LEVEL 



-10 -i 



1 10TT0. 1 



o 



2.3 1 
4.6' 
f 6.7' 



■20— 



■30 - 






■40 



9.5' 



12.8' 



15.3 
15.8' 



CORE NUMBER 40 
AREA A PROSPECT 2 



dark plastic clay 

very fine- to fine-grained sand 
dark plastic clay 

dark plastic clay with oyster shells 

very fine- to fine-grained sand with clay 

coarse-grained, yellow-brown gravel 
coarse-grained, dark-brown gravel with shell hash 



34 



SEA LEVEL 



■10 - 



iionnii 



^^-±-i 1.6' 



-20 - 






4.7' 



7.2' 



■30 



-40 



14.1 



LUKt NUPlBtK 41 
AREA A PROSPECT 1 



fine- to medium-grained sand 
dark plastic clay 



very fine- to fine-grained sand 



coarse shell hash with coarse-grained sand 



35 



q S EA LEVE L 



-in 



-20 



ISfflQ 






-30- 



-40 



6.6 1 ,1 
7.T 3! 



IT 



13.1 



CORE NUMBER 42 
AREA A PROSPECT 1 



very fine-grained sand 

as above with shell fragments 

very fine-grained sand with clay and oyster shells 

fine-grained, light-gray sand 
coarse-grained sand with wood fragments 



36 



SEA LEVEL 



-10 



BOTTOM n 



-20 



-30- 



-40 



0.5' - 
1.1 



'I 3: 



11.4' 



16.9' 



COPE NUMBER 43 
AREA A PROSPECT 1 



very fine-grained sand with clay 
as above with shell 



very fine-grained sand with few shells and some clay 



coarse shell hash with coarse-grained sand 



37 



SEA LEVEL 



■10- 



-20 -fc 



IlOTTO 



-30 



o 

1.0' 
2.0' 



T^TTTT^ 18.0' 



mm i8.9' 



-40 



CORE NUMBER M 
AREA A PROSPECT 1 



very fine-grained sand with some clay 
as above with shell 



very fine-grained sand with some clay; shell increasing with depth 



medium-grained, gray-yellow sand 



38 



SEA LEVEL 



-10 



CORE NUMBER 51 
AREA A PROSPECT 5 



lIpTTOHn 



-20 



-30 



-40 



9' 



12.6' 
13.6' 

15' 
16' 



very fine-grained sand with clay 



dark plastic clay 



very fine-grained sand with clay 

very fine- to fine-grained sand 

very fine- to fine-grained sand with shell hash 
as above 
as above 



Shell Unit Screen Analysis 



Screen Size 


Sample 


WT. 


Percent 


.0787" 


102.9 


gm 


19.5% 


.0394 


72.4 




13.7 


.0197 


216.7 




41.1 


.0098 


107.4 




20.4, 


.0049 


21.3 




4.0 


.0049> 


6.8 




1.3 



The commercial shell was retained on the 
0.0787" screen. These were clam shells. 
A 20% HC1 solution digested 60.1 gms or 
79.1% and left a residue of 42.8 qms or 
21%. 

The 3.4 foot segment analyzed contained 
.66 foot of shell. The analyzed section 
was not the oyster shell unit and there- 
fore was not mapped as reserves. 



39 



SEA LEV EL 



-10 



■20 



-30- 



3.0' 
3.7' 



6.0' 



8.2' 



-40 



14.4' 



KJKt NUHBtK bZ 
AREA A PROSPECT 5 



very fine- to fine-grained, tan-gray sand with some shell 

very fine- to fine-grained sand with clay 

very fine- to coarse-grained sand with dark plastic clay and 

oyster shells 



fine-grained sand 



fine- to medium- to coarse-grained sand with gravel 



Shell Unit Screen Analysis 



Screen Size 


Sample 


WT. 


Percent 


.1574" 


160.7 


gms 


29.8% 


.0787 


24.2 




4.5 


.0394 


32.5 




6.0 


.0197 


57.4 




10.6 


.0098 


87.4 




16.2 


. 0098 > 


177.4 




32.9 



The commercial shell was retained on the 
0.1574" screen. These were oyster shells 
A 20% HC1 solution digested 151.1 gms or 
94% and left a residue of 9.6 gms or 6%. 

The 2.3 foot segment analyzed contained 
0.68 foot of shell. 



40 



SEA LEV EL 



CORE NUMBER 55 
AREA A PROSPECT 2 



-10 - 



norm 






■r^r- 



3.0' 
4.0' 

6.0' 

7.4' 

10.0' 
11.0' 



very fine-grained sand and plastic clay with minor clam shells 

dark plastic clay 

dark plastic clay, fine-grained sand with oyster shells 

as above 

dark plastic clay, fine-grained sand 
medium- to coarse-grained sand with gravel 



-30- 



■40 



16.1 



fine- to medium-grained sand, interbedded yellow-tan-gray-black layers 



Shell Unit Screen Analysis 
Screen Size Sample WT . Percent 



.1574" 

.0787 

.0394 

.0197 

.0098 

.0098> 



154.7 gms 

13.8 

13.8 

15.2 

22.2 
199.0 



37.0% 
3.3 
3.3 
3.6 
5.3 

47.5 



The commercial shell was retained on the 
0.1574" screen. These were oyster shells. 
A 20% HC1 solution digested 153.2 gms or 99% 
and left a residue of 1.5 gms or 1%. 

The 3.4 foot segment analyzed con- 
tained 1.26 feet of shell. 



41 



SEA LEV EL 



CORE NUMBER 57 
AREA A PROSPECT 2 



-10- 



IIOTTOM 



-20 - : 



2.T ^ 
3.0' 



6.0' 

8.2' 
9.0' 



.mmm 12.0' 



•30- 



-40 



dark plastic clay 

as above with some sand and oyster shells 

as above 

as above 

fine- to medium-grained sand with clay; some shells 

fine- to medium-grained sand 



Shell Unit Screen Analysis 
Screen Size Sample WT . Percent 



.1574" 


187.8 gm 


36.7% 


.0787 


14.2 


2.8 


.0394 


12.1 


2.4 


.0197 


20.5 


3.9 


.0098 


2.6 


0.5 


.0098> 


275.0 


53.7 



The commercial shell was retained on 
the 0.1574" screen. These were oyster 
shells. A 20% HC1 solution digested 
186.8 gms or 99.5% and left a residue 
of 1.0 gms or 0.5%. 

The 6.1 foot segment analyzed contained 
2.24 feet of shell. 



42 



SEA LEVE L 



CORE NUMBER 58 
AREA A PROSPECT 3 



IlOTTOII 



-10- 



o 

1.2' 
3.6' 



very fine-grained sand 

very fine-grained sand with oyster shells 



10.0' 



-20 



-30- 



-40 



fine-grained sand with clay, some shell 



43 



SEA LEVEL 



-10 



-20 



4.8' 

7.T 
8.1' 



12. 9 1 



CORE NUMBER 59 
AREA A PROSPECT 3 



fine- to medium-grained sand 

dark plastic clay with sand 
plastic clay with oyster shells 

fine- to medium-grained sand with shell hash 



-30 



■40 



44 



SEA LEVEL 



toiwo 



■10 



-20- 



W2. 



■30 



■W 



1.8' 
3.0 1 

4.6' 

6.0' 

7.7' 

10.7' 



13.4' 
14' 



CORE NUMBER 60 
AREA A PROSPECT 3 



very fine- to fine-grained sand 
as above with scattered shells 
fine-grained sand with clay and shells 
dark plastic clay; sand with oyster shells 
clay as above grading to sand; no shells 

medium-grained sand with minor shell 

coarse-grained sand; some shell hash 
coarse-grained, tan sand with shell hash 



Shell Unit Screen Analysis 
Screen Size Sample WT . Percent 



.0787" 


76.6 gms 


15.6% 


.0394 


6.20 


1.3 


.0197 


11.80 


7.4 


.0098 


98.28 


20.0 


.0049 


140.00 


28.4 


.0049> 


149.42 


32.3 



The commercial shell was retained on the 
0.0787" screen. These were oyster shells. 
A 20% HC1 solution digested 73.3 gms or 
96.1% and left a residue of 3.0 gms or 3.9%. 

The 1.4 foot segment analyzed contained 0.22 
foot of shell . 



45 



APPENDIX 5: CORE HOLE LOCATIONS: RANGE-RANGE DATA 



Core 
No. 



Line 

Designation 



West Bridge 
Meters Feet 



East Bridge 
Meters Feet 



1 


Shipyard Channel 






Bridge 




2 


S-14-10 


4482 


14705 


5746 


18853 


3 


S-14-5 


4617 


15148 


5260 


17258 


4 


TV-A 


6253 


20516 


7065 


23180 


5 


TV -30 


6394 


20979 


6062 


19889 


6 


T-19 


7844 


25736 


5875 


19276 


7 


U-21-6 


9659 


31691 


8130 


26675 


8 


U-23-1 


10776 


35356 


9581 


31435 


9 


U-24 


12010 


39405 


11010 


36124 


10 


V-25-4 


12535 


41127 


12037 


39493 


11 


V-26 


13228 


43401 


12909 


42354 


12 


V-27-12 


9907 


32505 


9907 


32505 


13 


V-28-7 


8477 


27813 


8430 


27659 


14 


VS-T-31 


4897 


16067 


4680 


15355 


15 


VR-T-32 


3885 


12747 


3672 


12048 


16 


VQ-T-33 


3132 


10276 


2710 


8892 


17 


VP-T-34 


2610 


8563 


2546 


8353 


18 


V-35 


2196 


7205 


2311 


7582 


19 


P-5 


4450 


14600 


1096 


3596 


20 


Q-6 


5180 


16996 


1956 


6418 


21 


R-ll 


5701 


18705 


3100 


10171 


22 


S-13 


6655 


21835 


4210 


13813 


23 


P-2 


1183 


3881 


4605 


15109 


24 


Q-8 


2220 


7284 


4647 


15247 


25 


R-9 


3400 


11155 


5106 


16753 


26 


S-15 


4572 


15001 


6086 


19968 


2 7 


T-16 


5893 


19335 


7223 


23699 


23 


N-28-11 


12701 


41672 


215 


705 


29 


4WN-T 


13338 


43762 


847 


2779 


30 


4WM-T 


13091 


42952 


1157 


3796 


31 


4W-2-4 


12857 


42184 


1800 


5906 


32 


4WL-T-3 


12857 


42184 


2585 


8481 


33 


4WK-T-22 


12729 


41764 


3148 


10329 


34 


4WJ-T-19 


12552 


41183 


4424 


14515 


35 


4W-5 


12580 


41275 


5225 


17143 


36 


4WI-T 


12655 


41521 


6100 


20014 


37 


4WH-T 


12884 


42272 


6917 


22695 


38 


4WG-T 


13316 


43690 


7905 


25936 


39 


4WF-T 


14030 


46032 


8662 


28420 


40 


4WE-T 


14837 


48680 


9661 


31698 


41 


4WD-T 


15466 


50744 


10659 


34972 


42 


4WC-T 


16221 


53221 


11725 


38470 


43 


4WB-T 


16920 


55515 


12632 


41446 


44 


4WA-T 


17285 


56712 


13108 


43007 


45 


AB-T-(B-2) 


17397 


57080 


12599 


41337 


46 


C-5± 


16312 


53520 


11352 


37246 


4 7 


D-6± 


15647 


51338 


10437 


34244 


4? 


E-9± 


15142 


49681 


9353 


30687 


49 


F-10+ 


14501 


47578 


8682 


28486 


50 


G-12-10± 


14065 


46147 


7762 


25467 


51 


M-26 


11204 


36760 


1725 


5660 


52 


L-25 


11397 


37394 


2315 


7596 


53 


K-21 


11202 


37654 


3636 


11930 


54 


J-20 


11661 


38260 


4378 


14364 


55 


H-15 


12465 


40898 


7083 


23239 


56 


G-12 


12950 


42489 


8163 


26783 


57 


F-ll 


13508 


44320 


8863 


29080 


58 


2W/1S-12+ 


9607 


31521 


6230 


20441 


59 


2W/2S-T-12-6 


9875 


32400 


5002 


16412 


60 


4S ext. 


9580 


31432 


3510 


11516 



46 



APPENDIX 6: FUTURE CORE POINTS 



Line Designation 



Locat 


ion* 


PM3 


MM7 


PM1 


MM7 


PM2 




PM3 


MM5 




MM9 


PM4 


MM3 


PM1 


MM2 


PM3 


MM8 


PM4 


MM4 


PM5 


MM4 


PM6 


MM3 


PM5 


MM4 


PM3 


MM! 


PM1 


MM2 


PM2 


MM7 


PM12 




PM8 


MM2 


PM6 


MM5 


PM6 


MM! 


PM1 


MM2 


PM4 


MM4 


PM4 


MM9 


PM7 




PM9 


MM5 


PM8 




PM9 




PM10 


MM6 


PM14 


MM3 


PM26 


MM3 


PM17 


MM2 


PM10 


MM2 


PM15 




PM7 


MM4 


PM6 


MM4 


PM4 


MM3 


PM1 


MM5 


PM11 


MM5 


PM11 




PM8 




PM6 


MM4 


PM2 


MM! 2 


PM2 


MM16 


PM2 


MM28 


PM2 


MM31 


PM1 


MM10 


PM1 


MM125 


PM1 


MM5 


PM2 


MM6 



ne Designation 


Location* 


IS 


PM1 


MM17 




PM1 


MM8 




PM1 






PM1 


MM3 


C 


PM4 


MM1 


DE 


PM7 


MM4 


E 


PM8 


MM! 


FG 


PM11 


MM 3 


G 


PM12 


MM2 




PM12 


MM6 


H 


PM14 


MM6 




PM14 


MM 10 


HI 


PM15 


MM5 


I 


PM16 


MM7 




PM16 


MM10 


L 


PM24 


MM 16 




PM25 


MM 3 




PM26 


MM3 




PM26 


MM8 




PM26 


MM10 


P 


PM4 


MM5 


o. 


PM7 


MM2 




PM13 


MM6 




PM13 


MM9 




PM13 


MM15 


T 


PM16 


MM6 




PM17 


MM3 




PM17 


MM5 


U 


PM23 


MM6 




PM20 


MM6 


V 


PM25 


MM4 




PM25 


MM 10 




PM26 


MM5 




PM27 


MM13 


2W 


PM12 
PM15 


MM3 


3W 


PM1 


MM 7 


IN shadow 


PM3 




2N shadow 


PM4 
PM3 


MM3 


4N shadow 


PM2 


MM8 




PM1 


MM5 


5N shadow 


PM1 


MM11 


3S ext 


PM7 


MM3 




PM1 


MM5 


5S ext 


PM3 


MM6 



16N 
15N 
14N 



13N 
13 



12N 

ION 

9N 
8N 

7N rerun 

6N 

5N 
4N west 

3N 
2N 

IN 



* PM refers to Position Mark and MM to Minute Mark and are so indicated on the seismic lines and ranqe- 
range data. 



47 



SMC DEMS LIBRARY 
1610 IV5SC 

RALEjOK.NC 27699-1 6 1 
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